In so-called direct-coupled wind power turbines of the above type (i.e., with no reducer between the blade assembly and the rotor), one of the components requiring most frequent maintenance and/or replacement is the bearing means, which normally comprise one or more relatively large-diameter bearings interposed between the blade assembly shaft and the stator of the electric generator.
To simplify maintenance and/or replacement, wind power turbines of the above type have been devised, in which the bearings can be worked on, after disconnecting the shaft from the blade assembly hub, from inside the nacelle, without having to detach and lower the blade assembly to the ground.
In known wind power turbines of this type, the shaft and bearings can obviously only be disconnected after angularly locking the blade assembly with respect to the stator.
In known wind power turbines of the above type, angularly locking the blade assembly normally involves first positioning the blade assembly angularly with respect to the stator, in that locking can normally only be achieved by selectively setting the blade assembly to a given number of angular positions with respect to the nacelle.
Given the size and the sensitivity to external agents of the blade assemblies employed, setting the blade assembly to given angular positions with respect to the nacelle is rarely fast or easy.